Improvement in circular saws



at v e? L a duit-eil tant atnt (was.

Leum patear No. 87,891, dated Jamais, 1869. i,

yIMAPRQ'V'IEHWENT IN CIRCULAR. SAWS.

The Schedule referred to in these Letters Patent and making pari: of`the same Be it known that we, J con WEIBLE and- Humm S. ROBINSON, bothcitizens of the United States, and

. residents of Detroit, in the State of Michigan, have invented a newand improved Smooth-Cutting Orosseut Circular Saw; and we hereby declarethat the following is fa full and exact description thereof, referencebeing had to the accompanying drawings, and to the jletters' ofreference marked thereon.

We -ventxue an explanatory remark or two, by way of bringing out moreclearly the nature and benefit of this invention.

All circular crosscut-saws hitherto in use, are found to rip, or tearthrough the wood to which they are applied, leaving a rough and uneven,or ragged surface on both sides -of the material sawed. For this reason,

alsoit was found to `be almost ,impossible touse with advantage'thecrosscut circular saw in dividing thin woods, such as are used formaking light boxes, like cigar-boxes, &c., andY when woods were lso cnt,they were lleft with ragged edges, requiring the additional labor andapplication of a plane.

The saw herein described cuts through the thinnest boards, and makesbthsides equally smooth and clean,

` and quite as even as if they had been delicately planed.

It will also cut through spongy, or soft wood, or other material, suchas cork, giving smooth sides as it passes. The lumber thus cut can beput directlyinto boxes,

without the necessity of smoothing or planing.

steel, of the diameter desired, circular in shape, with theordinary'hole for the vmandrel in the centre, as ,is represented in thedrawings herewith, marked A.

Then, with a small square file, we proceed to coul struct the teetharound the entire saw, by filing o the edge thereof to the width (on aten-inch diameter saw,

such as is represented on the drawing, marked B,) of three-sixteeuths ofan inch, and a depth, or length of about one-eighth of an inch,imparting to each tooth thus made a knife-like edge, or sharpness on thefront and upper line thereof, such front line, on a saw of ten inchesdiameter, being perpendicular to the axis, and a trifle, say thethirty-secoudth (gf), of an inch, shorter indepth than the rear line ofsaid tooth: 1 These teeth are constructed around the edge of the saw,atan angle of, say, eighty degrees with the saw itself, and are thusalternately and successively inclined right and left about and aroundthe entire edge ofthe saw. 'Being thus sharpened, they cut their waythrough the wood as a knife or plane, without tearing or roughening thesurface, as is the manner of ordinaryci'rcular saws. i

Saws of largeidiameter and heavier form,a nd designed for sawing heavierwoods, may be and are, in ourconstruction of them, furnished with teethproportionally largeriu size than are those of the saw alreadydescribed; and these teeth are made in the way they are ordinarilyconstructed on circular saws. They are then led twothirds or one-halfthe way down, so as to give them a sharp, or kuife-likeedge on theupperline thereof, and on the front edge they are likewiseso sh'arpened,4wholly or partially, as may be desired. Theseteeth are then set with analternate right and left inclination around the edge of the saw, as hasbeen already described, and at about the same angle with the axis of thesaw. They are represented in the drawing, marked O.

We disclaim any invention as to the mere form of the saw as a circularsaw.

What we claim as our invention, is-

'lhe improved mode `of constructingcircular saws,V as herein shown anddescribed, and for thepurpose set forth.

JACOB WEIBLE.

HENRY S. ROBINSON.

' -Witnessesz HENRY M. DUFFmLD,

D. BETHUNE DUFFIELD.

